Control agents for living-type free radical polymerization, methods of polymerizing and polymers with same

ABSTRACT

Control agents that have a nitrogen-nitrogen bond covalently bonded to a thiocarbonyl moiety are provided for living-type free radical polymerization of a wide variety of monomers. These control agents provide superior properties for control of the polymerization and/or the properties of the polymers obtained and/or the monomers that may be polymerized. In some embodiments, a bulky group is pendant off the activated thiocarbonyl portion of the control agents. Multifunctional control agents provide the opportunity for a variety of structurally unique polymers, including block copolymers, stars and hyper-branched polymers.

FIELD OF THE INVENTION

[0001] The present invention relates to new compounds useful inassisting in the polymerization of monomers in a free radicalpolymerization that has living-type kinetics. Polymers made with thecontrol agents and processes for polymerization are also included. Inaddition, some of the compounds themselves are novel.

BACKGROUND OF THE INVENTION

[0002] The use and mechanism of control agents for free radicalpolymerization is now generally known, see for example WO98/01478,WO99/35177, WO99/31144, and WO98/58974, each of which is incorporatedherein by reference. Despite this knowledge, no successfulcommercialization of a polymerization process has occurred with theseagents. Thus the need for new agents, which lead to a commercializableprocess are needed.

[0003] In addition, the previously known control agents have limiteduses. Although touted as universally useful, those of skill in the artappreciate that a particular control agent is particularly useful forthe control of particular monomers and monomer mixtures. Thepolymerization conditions under which particular control agents areparticularly useful are generally not well known. Thus, a need existsfor a family of related control agents that can be easily synthesizedand modified so that a control agent will be readily available forpolymerizing desired monomers under commercially acceptable conditions,which include high conversion at the shortest possible reaction timesand lower temperatures.

[0004] This invention solves these issues by providing control agentsthat can be easily modified for particular monomers and monomermixtures. The control agents of the present invention contain at leastone nitrogen-nitrogen bond, which allows for simpler modification of theelectronic and steric nature of the control agents as compared to knowncontrol agents. These modified properties allow for improved conditionsof the polymerization process and/or improved properties of the polymersobtained from the processes.

SUMMARY OF THE INVENTION

[0005] This invention provides control agents that are easy to prepareand economically useful on a commercial scale. In particular, thecontrol agents of this invention have a nitrogen-nitrogen bond, which isbelieved to provide better chemical stability of the control agenttogether with a greater flexibility for chemical modification of saidcontrol agents, while giving control of a polymerization reaction thatincludes a free radical.

[0006] In general, the control agents of this invention have a N—N bondcovalently bonded to a thiocarbonyl moiety. In some embodiments thecontrol agents can be characterized by the general formula:

[0007] wherein D is S, Te or Se; R¹ is generally any group that issufficiently labile to be expelled as its free radical form; R² and R³are each independently selected from the group consisting of hydrogen,hydrocarbyl, substituted hydrocarbyl, heteroatom-containing hydrocarbyl,and substituted heteroatom-containing hydrocarbyl, and combinationsthereof, and R⁴ is selected from the group consisting of hydrogen,hydrocarbyl, substituted hydrocarbyl, heteroatom-containing hydrocarbyl,and substituted heteroatom-containing hydrocarbyl, and combinationsthereof; and optionally, R⁴ combines with R² to form a ring structure,with said ring having from 3 to 50 non-hydrogen atoms. In someembodiments, R² can form a ring structure with R¹, as discussed herein.

[0008] Another aspect of this invention is directed towardmulti-functional control agents, so that the control agents may occupyeither a central portion of a polymer chain and/or two or more ends of apolymer. In those embodiments where the control agent occupies a centralportion of the polymer backbone, the nitrogen-nitrogen bond provides theunique opportunity to degrade the polymer backbone into smaller piecesby external stimuli (e.g., heat, chemical reaction, irradiation, etc.).Such a process is unique as compared to known free radicalpolymerization and “living” free radical polymerization techniques. Inaddition, some of the multi-functional control agents are cyclic, whichprovide the unique opportunity to prepare block copolymers with reducedprocesses steps. Furthermore, some multi-functional control agents allowfor ring opening polymerizations, which heretofore have not foundcommercial applications in free radical polymerization.

[0009] Other aspects of this invention include certain of the controlagents, which are novel compounds. Polymerization processes using all ofthe control agents of this invention and polymers that can be made withthe control agents of this invention are additional aspects of thisinvention. In particular, the control agents of this invention provideliving-type kinetics and as such allow for the preparation of desiredproducts, including block polymers, star architectures, grafts andhyperbranched polymers.

[0010] Thus, it is an object of this invention to provide novel controlagents for a living-type free radical polymerization process.

[0011] It is another object of this invention to provide novelcompounds, which are useful as control agents in a free radicalpolymerization process.

[0012] It is a further object of this invention to provide a novelsystem for free radical polymerization of monomers that employsliving-type kinetics.

[0013] It is still a further object of this invention to polymerize avariety of monomers under commercially acceptable conditions with afamily of control agents.

[0014] It is yet a further object of this invention to make controlledarchitecture polymers with a polymerization process that employs acontrol agent.

[0015] It is further another object of this invention to providemultifunctional control agents that may occupy a central portion of apolymer chain allowing for the polymer chain to be degraded.

[0016] Further aspects and objects of this invention will be evident tothose of skill in the art upon review of this specification.

DETAILED DESCRIPTION OF THE INVENTION

[0017] In the most general terms, the control agents of this inventioncontain at least one N¹—N² bond covalently bonded to a thiocarbonylgroup. In structural terms, the following moiety must be present in thecontrol agents of this invention:

[0018] In some embodiments, a sulfur atom is attached to thethiocarbonyl group, leading to a dithiocarbonyl moiety. This may bereferred to herein as the “dithiocarbazate” group or N—NC(═S)S moiety,however, such terminology is not intended to be limiting. Also, in someembodiments, the substituents of N² (other than N¹) should not form aheterocycle that includes N²

[0019] In describing and claiming the present invention, the followingterminology will be used in accordance with the definitions set outbelow. A named R group will generally have the structure that isrecognized in the art as corresponding to R groups having that name. Forthe purposes of illustration, representative R groups as enumeratedabove are defined herein. These definitions are intended to supplementand illustrate, not preclude, the definitions known to those of skill inthe art.

[0020] It is also to be understood that the terminology used herein isfor the purpose of describing particular embodiments only, and is notintended to be limiting. As used in this specification and the appendedclaims, the singular forms “a,” “an” and “the” include plural referentsunless the context clearly dictates otherwise. In describing andclaiming the present invention, the following terminology will be usedin accordance with the definitions set out below.

[0021] The following definitions pertain to chemical structures,molecular segments and substituents:

[0022] As used herein, the phrase “having the structure” is not intendedto be limiting and is used in the same way that the term “comprising” iscommonly used. The term “independently selected from the groupconsisting of” is used herein to indicate that the recited elements,e.g., R groups or the like, can be identical or different (e.g., R² andR³ in the structure of formula (1) may all be substituted alkyl groups,or R² may be hydrido and R³ may be methyl, etc.).

[0023] “Optional” or “optionally” means that the subsequently describedevent or circumstance may or may not occur, and that the descriptionincludes instances where said event or circumstance occurs and instanceswhere it does not. For example, the phrase “optionally substitutedhydrocarbyl” means that a hydrocarbyl moiety may or may not besubstituted and that the description includes both unsubstitutedhydrocarbyl and hydrocarbyl where there is substitution.

[0024] The term “alkyl” as used herein refers to a branched orunbranched saturated hydrocarbon group typically although notnecessarily containing 1 to about 24 carbon atoms, such as methyl,ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, octyl, decyl,and the like, as well as cycloalkyl groups such as cyclopentyl,cyclohexyl and the like. Generally, although again not necessarily,alkyl groups herein contain 1 to about 12 carbon atoms. The term “loweralkyl” intends an alkyl group of one to six carbon atoms, preferably oneto four carbon atoms. “Substituted alkyl” refers to alkyl substitutedwith one or more substituent groups, and the terms“heteroatom-containing alkyl” and “heteroalkyl” refer to alkyl in whichat least one carbon atom is replaced with a heteroatom.

[0025] The term “alkenyl” as used herein refers to a branched orunbranched hydrocarbon group typically although not necessarilycontaining 2 to about 24 carbon atoms and at least one double bond, suchas ethenyl, n-propenyl, isopropenyl, n-butenyl, isobutenyl, octenyl,decenyl, and the like. Generally, although again not necessarily,alkenyl groups herein contain 2 to about 12 carbon atoms. The term“lower alkenyl” intends an alkenyl group of two to six carbon atoms,preferably two to four carbon atoms. “Substituted alkenyl” refers toalkenyl substituted with one or more substituent groups, and the terms“heteroatom-containing alkenyl” and “heteroalkenyl” refer to alkenyl inwhich at least one carbon atom is replaced with a heteroatom.

[0026] The term “alkynyl” as used herein refers to a branched orunbranched hydrocarbon group typically although not necessarilycontaining 2 to about 24 carbon atoms and at least one triple bond, suchas ethynyl, n-propynyl, isopropynyl, n-butynyl, isobutynyl, octynyl,decynyl, and the like. Generally, although again not necessarily,alkynyl groups herein contain 2 to about 12 carbon atoms. The term“lower alkynyl” intends an alkynyl group of two to six carbon atoms,preferably three or four carbon atoms. “Substituted alkynyl” refers toalkynyl substituted with one or more substituent groups, and the terms“heteroatom-containing alkynyl” and “heteroalkynyl” refer to alkynyl inwhich at least one carbon atom is replaced with a heteroatom.

[0027] The term “alkoxy” as used herein intends an alkyl group boundthrough a single, terminal ether linkage; that is, an “alkoxy” group maybe represented as —O-alkyl where alkyl is as defined above. A “loweralkoxy” group intends an alkoxy group containing one to six, morepreferably one to four, carbon atoms. The term “aryloxy” is used in asimilar fashion, with aryl as defined below.

[0028] Similarly, the term “alkyl thio” as used herein intends an alkylgroup bound through a single, terminal thioether linkage; that is, an“alkyl thio” group may be represented as —S-alkyl where alkyl is asdefined above. A “lower alkyl thio” group intends an alkyl thio groupcontaining one to six, more preferably one to four, carbon atoms.

[0029] The term “allenyl” is used herein in the conventional sense torefer to a molecular segment having the structure —CH═C═CH₂. An“allenyl” group may be unsubstituted or substituted with one or morenon-hydrogen substituents.

[0030] The term “aryl” as used herein, and unless otherwise specified,refers to an aromatic substituent containing a single aromatic ring ormultiple aromatic rings that are fused together, linked covalently, orlinked to a common group such as a methylene or ethylene moiety. Thecommon linking group may also be a carbonyl as in benzophenone, anoxygen atom as in diphenylether, or a nitrogen atom as in diphenylamine.Preferred aryl groups contain one aromatic ring or two fused or linkedaromatic rings, e.g., phenyl, naphthyl, biphenyl, diphenylether,diphenylamine, benzophenone, and the like. In particular embodiments,aryl substituents have 1 to about 200 carbon atoms, typically 1 to about50 carbon atoms, and preferably 1 to about 20 carbon atoms. “Substitutedaryl” refers to an aryl moiety substituted with one or more substituentgroups, (e.g., tolyl, mesityl and perfluorophenyl) and the terms“heteroatom-containing aryl” and “heteroaryl” refer to aryl in which atleast one carbon atom is replaced with a heteroatom.

[0031] The term “aralkyl” refers to an alkyl group with an arylsubstituent, and the term “aralkylene” refers to an alkylene group withan aryl substituent; the term “alkaryl” refers to an aryl group that hasan alkyl substituent, and the term “alkarylene” refers to an arylenegroup with an alkyl substituent.

[0032] The terms “halo” and “halogen” are used in the conventional senseto refer to a chloro, bromo, fluoro or iodo substituent. The terms “haloalkyl,” “haloalkenyl” or “haloalkynyl” (or “halogenated alkyl,”“halogenated alkenyl,” or “halogenated alkynyl”) refers to an alkyl,alkenyl or alkynyl group, respectively, in which at least one of thehydrogen atoms in the group has been replaced with a halogen atom.

[0033] The term “heteroatom-containing” as in a “heteroatom-containinghydrocarbyl group” refers to a molecule or molecular fragment in whichone or more carbon atoms is replaced with an atom other than carbon,e.g., nitrogen, oxygen, sulfur, phosphorus or silicon. Similarly, theterm “heteroalkyl” refers to an alkyl substituent that isheteroatom-containing, the term “heterocyclic” refers to a cyclicsubstituent that is heteroatom-containing, the term “heteroaryl” refersto an aryl substituent that is heteroatom-containing, and the like. Whenthe term “heteroatom-containing” appears prior to a list of possibleheteroatom-containing groups, it is intended that the term apply toevery member of that group. That is, the phrase “heteroatom-containingalkyl, alkenyl and alkynyl” is to be interpreted as“heteroatom-containing alkyl, heteroatom-containing alkenyl andheteroatom-containing alkynyl.”

[0034] “Hydrocarbyl” refers to univalent hydrocarbyl radicals containing1 to about 30 carbon atoms, preferably 1 to about 24 carbon atoms, mostpreferably 1 to about 12 carbon atoms, including branched or unbranched,saturated or unsaturated species, such as alkyl groups, alkenyl groups,aryl groups, and the like. The term “lower hydrocarbyl” intends ahydrocarbyl group of one to six carbon atoms, preferably one to fourcarbon atoms. “Substituted hydrocarbyl” refers to hydrocarbylsubstituted with one or more substituent groups, and the terms“heteroatom-containing hydrocarbyl” and “heterohydrocarbyl” refer tohydrocarbyl in which at least one carbon atom is replaced with aheteroatom.

[0035] By “substituted” as in “substituted hydrocarbyl,” “substitutedaryl,” “substituted alkyl,” “substituted alkenyl” and the like, asalluded to in some of the aforementioned definitions, is meant that inthe hydrocarbyl, hydrocarbylene, alkyl, alkenyl or other moiety, atleast one hydrogen atom bound to a carbon atom is replaced with one ormore substituents that are functional groups such as hydroxyl, alkoxy,thio, phosphino, amino, halo, silyl, and the like. When the term“substituted” appears prior to a list of possible substituted groups, itis intended that the term apply to every member of that group. That is,the phrase “substituted alkyl, alkenyl and alkynyl” is to be interpretedas “substituted alkyl, substituted alkenyl and substituted alkynyl.”Similarly, “optionally substituted alkyl, alkenyl and alkynyl” is to beinterpreted as “optionally substituted alkyl, optionally substitutedalkenyl and optionally substituted alkynyl.”

[0036] As used herein the term “silyl” refers to the —SiZ¹Z²Z³ radical,where each of Z¹, Z², and Z³ is independently selected from the groupconsisting of hydrido and optionally substituted alkyl, alkenyl,alkynyl, aryl, aralkyl, alkaryl, heterocyclic, alkoxy, aryloxy andamino.

[0037] As used herein, the term “phosphino” refers to the group —PZ¹Z²,where each of Z¹ and Z² is independently selected from the groupconsisting of hydrido and optionally substituted alkyl, alkenyl,alkynyl, aryl, aralkyl, alkaryl, heterocyclic and amino.

[0038] The term “amino” is used herein to refer to the group —NZ¹Z²,where each of Z¹ and Z² is independently selected from the groupconsisting of hydrido and optionally substituted alkyl, alkenyl,alkynyl, aryl, aralkyl, alkaryl and heterocyclic.

[0039] The term “thio” is used herein to refer to the group —SZ¹, whereZ¹ is selected from the group consisting of hydrido and optionallysubstituted alkyl, alkenyl, alkynyl, aryl, aralkyl, alkaryl andheterocyclic.

[0040] As used herein all reference to the elements and groups of thePeriodic Table of the Elements is to the version of the table publishedby the Handbook of Chemistry and Physics, CRC Press, 1995, which setsforth the new IUPAC system for numbering groups.

[0041] This invention provides novel compounds and control agents usefulfor the control of free radical polymerization reactions. In general afree radical polymerization is carried out with these control agents bycreating a mixture of at least one polymerizable monomer, the controlagent and optionally at least one source of free radicals, e.g., aninitiator. The source of free radicals is optional because some monomersmay self-initiate upon heating. After or upon forming the polymerizationmixture, the mixture is subjected to polymerization conditions.Polymerization conditions are those conditions that cause the at leastone monomer to form at least one polymer, as discussed herein, such astemperature, pressure, atmosphere, ratios of starting components used inthe polymerization mixture, reaction time or external stimuli of thepolymerization mixture.

[0042] Control Agents

[0043] Generally, the control agents of this invention may becharacterized by the general formula (I′) above. More specifically, thecontrol agents of this invention may be characterized by the generalformula:

[0044] wherein D is S, Te or Se. Preferably, D is sulfur. R¹ isgenerally any group that can be easily expelled under its free radicalform (R¹•) upon an addition-fragmentation reaction, as depicted below inScheme 1 (showing D as S):

[0045] In Scheme 1, P• is a free radical, typically a macro-radical,such as polymer chain. More specifically, R¹ is selected from the groupconsisting of hydrocarbyl, substituted hydrocarbyl,heteroatom-containing hydrocarbyl, and substituted heteroatom-containinghydrocarbyl, and combinations thereof. Even more specifically, R¹ isselected from the group consisting of optionally substituted alkyl,optionally substituted aryl, optionally substituted alkenyl, optionallysubstituted alkoxy, optionally substituted heterocyclyl, optionallysubstituted alkylthio, optionally substituted amino and optionallysubstituted polymer chains. And still more specifically, R¹ is selectedfrom the group consisting of —CH₂Ph, —CH(CH₃)CO₂CH₂CH₃, —CH(CO₂CH₂CH₃)₂,—C(CH₃)₂CN, —CH(Ph)CN and —C(CH₃)₂Ph.

[0046] Also, R² and R³ are each independently selected from the groupconsisting of hydrogen, hydrocarbyl, substituted hydrocarbyl,heteroatom-containing hydrocarbyl, and substituted heteroatom-containinghydrocarbyl, and combinations thereof. More specifically, R² and R³ maybe each independently selected from the group consisting of hydrogen,optionally substituted alkyl, optionally substituted aryl, optionallysubstituted alkenyl, optionally substituted acyl, optionallysubstituted, aroyl, optionally substituted alkoxy, optionallysubstituted heteroaryl, optionally substituted heterocyclyl, optionallysubstituted alkylsulfonyl, optionally substituted alkylsulfinyl,optionally substituted alkylphosphonyl, optionally substitutedarylsulfinyl, and optionally substituted arylphosphonyl. Specificembodiments of R² and/or R³ are listed in the above definitions, and inaddition include perfluorenated aromatic rings, such as perfluorophenyl.Also optionally, R² and R³ can together form a double bond alkenylmoiety off the nitrogen atom, and in that case R² and R³ are togetheroptionally substituted alkenyl moieties.

[0047] Finally, R⁴ is selected from the group consisting of hydrogen,hydrocarbyl, substituted hydrocarbyl, heteroatom-containing hydrocarbyl,and substituted heteroatom-containing hydrocarbyl, and combinationsthereof; and optionally, R⁴ combines with R² and/or R³ to form a ringstructure, with said ring having from 3 to 50 non-hydrogen atoms. Inparticular, R⁴ is selected from the group consisting of hydrogen,optionally substituted alkyl, optionally substituted aryl, optionallysubstituted alkenyl, optionally substituted acyl, optionally substitutedaroyl, amino, thio, optionally substituted aryloxy and optionallysubstituted alkoxy. Preferred R⁴ groups include methyl and phenyl.

[0048] In a more specific. embodiment, a bulky moiety is attached to theN¹ nitrogen atom, which in some embodiments may be characterized by thegeneral formula:

[0049] wherein D and R¹-R⁴ are as defined above and Q is selected fromthe group consisting of carbon, sulfur and. phosphorus (C, S and P); Q′is selected from the group consisting of oxygen and sulfur (O and S);R^(4′) is typically selected from the same group as R⁴; and n, m and pare each either 0, 1 or 2 to satisfy the valency of Q. Thus, forexample, when Q is carbon, n and p may both be 1 and m is 0. Anotherexample for when Q is carbon is that n is 1 and m is 1 and p is 0. Alsofor example, when Q is phosphorus, n is 1 and m is 2. Also for example,when Q is sulfur, n is 1 or 2, but typically 2; and m is typically 0 andp is 1. In some preferred embodiments, Q is carbon or sulfur and Q′ isoxygen. In these preferred embodiments, R⁴ and R^(4′) are eachindependently more preferably selected from the group consisting ofoptionally substituted alkyl and optionally substituted aryl.

[0050] In some embodiments within formulas (I) and (II), above, R²and/or R³ may be independently selected from—Q(═Q′)_(n)(R^(4′)—Q′)_(m)(R⁴)_(p), which is the moiety from the N¹ atomin formula (II), with the N¹ atoms being identified in formula (I′). Inthese embodiments, Q, Q′, R⁴, R^(4′), n, m and p have the above stateddefinitions.

[0051] Some of the control agents are novel compounds. In someembodiments, the novel compounds may be characterized by the aboveformula (II). More specifically, novel compounds may be characterized bythe formula:

[0052] wherein R¹ is selected from the group consisting of hydrocarbyl,substituted hydrocarbyl, heteroatom-containing hydrocarbyl, andsubstituted heteroatom-containing hydrocarbyl, and combinations thereof,with the proviso that R¹ is not methyl;

[0053] R² and R³ are each independently selected from the groupconsisting of hydrogen, hydrocarbyl, substituted hydrocarbyl,heteroatom-containing hydrocarbyl, and substituted heteroatom-containinghydrocarbyl, and combinations thereof; and

[0054] R⁴ is selected from the group consisting of hydrogen,hydrocarbyl, substituted hydrocarbyl, heteroatom-containing hydrocarbyl,and substituted heteroatom-containing hydrocarbyl, and combinationsthereof; and optionally, R⁴ combines with R² to form a ring structure,with said ring having from 3 to 50 non-hydrogen atoms. In more specificembodiments, R¹-R⁴ are selected from the lists given above.

[0055] In some embodiments within formula (III), R² and/or R³ may beindependently selected from —Q(═Q′)_(n)(R^(4′)—Q′)_(m)(R⁴)_(p). In theseembodiments, Q, Q′, R⁴, R^(4′), n, m and p have the above stateddefinitions.

[0056] Also more specifically, the novel compounds may be characterizedby the formula:

[0057] wherein R¹ is selected from the group consisting of hydrocarbyl,substituted hydrocarbyl, heteroatom-containing hydrocarbyl, andsubstituted heteroatom-containing hydrocarbyl, and combinations thereof;

[0058] R² and R³ are each independently selected from the groupconsisting of hydrogen, hydrocarbyl, substituted hydrocarbyl,heteroatom-containing hydrocarbyl, and substituted heteroatom-containinghydrocarbyl, and combinations thereof, and optionally, R² and R³ arejoined together in a ring structure having between 3 and 50 non-hydrogenatoms in said ring; and

[0059] R⁴ is selected from the group consisting of hydrogen,hydrocarbyl, substituted hydrocarbyl, heteroatom-containing hydrocarbyl,and substituted heteroatom-containing hydrocarbyl, and combinationsthereof; and optionally, R⁴ combines with R² to form a ring structure,with said ring having from 3 to 50 non-hydrogen atoms. In more specificembodiments, R¹-R⁴ are selected from the lists given above.

[0060] In some embodiments within formula (IV), R² and/or R³ may beindependently selected from —Q(═Q′)_(n)(R^(4′)—Q′)_(m)(R⁴)_(p). In theseembodiments, Q, Q′, R⁴, R^(4′), n, m and p have the above stateddefinitions.

[0061] In more specific embodiments, the groups of the novel compoundscan have R¹ is selected from the group consisting of optionallysubstituted alkyl, optionally substituted aryl, optionally substitutedalkenyl, optionally substituted alkoxy, optionally substitutedheterocyclyl, optionally substituted alkylthio, optionally substitutedamino and optionally substituted polymer chains. Even more specifically,R¹ is selected from the group consisting of —CH₂Ph, —CH(CH₃)CO₂CH₂CH₃,—CH(CO₂CH₂CH₃)₂, —C(CH₃)₂CN, —CH(Ph)CN and —C(CH₃)₂Ph. Also, R² and R³may be each independently selected from the group consisting ofhydrogen, optionally substituted alkyl, optionally substituted aryl,optionally substituted alkenyl, optionally substituted acyl, optionallysubstituted, aroyl, optionally substituted alkoxy, optionallysubstituted heteroaryl, optionally substituted heterocyclyl, optionallysubstituted alkylsulfonyl, optionally substituted alkylsulfinyl,optionally substituted alkylphosphonyl, optionally substitutedarylsulfinyl, and optionally substituted arylphosphonyl. Further, R⁴ maybe selected from the groups listed above.

[0062] Specific control agents within these formulas include:

[0063] This invention also includes multi-functional control agents andtheir use in free radical polymerization. A multi-functional controlagent is a molecule that allows for two or more polymer chains topolymerize from a single control agent molecule. In some embodiments,the control agents are attached to a core that has multiple functionalsites for attachment of one portion of a control agent. Thus, in someembodiments, R², R³ and/or R⁴ forms part of or is attached to a coremolecule. In other embodiments, R¹ is part of or attached to a coremolecule. These multi-functional chain transfer agents may becharacterized by any of the following general formulas:

[0064] wherein Core is a core molecule, and D, R¹, R², R³ and R⁴ are asdefined above, c is 1 or more and d is 2 or more. Formulas (V), (VI) and(VII) include multiple core molecules, providing many possible pointsfrom which a free radical polymerization may be controlled. Thisprovides the ability to make may different architectures for polymers,some of which are discussed below. For example, for a star architecturepolymer c is 1 and d is 3 for a three arm star; c is 1 and d is 4 for a4 arm star; c is 1 and d is 6 for a six arm star; etc. Also for example,for a grafted polymer, c is 1 and d is 2 for two grafts, etc. For ahyper-branched polymer, c is 2 or more and d is 2 or more.

[0065] The multifunctional chain transfer agents may also be drawn forthe more specific embodiments of this invention, as follows:

[0066] wherein Core, Q, Q′, n, c, d, D, R¹, R², R³ and R⁴ are as definedabove.

[0067] The Core molecule may be selected from the group consisting ofdendritic molecules, small molecules and polymers with at least twoterminus ends. Thus, Core molecule may be optionally substitutedhydrocarbyl and optionally substituted heteroatom containinghydrocarbyl. Specific examples of Core molecules include:

[0068] In other embodiments, the Core will be a polymer chain. Theseembodiments allow for the preparation of grafts or block copolymers byattaching control agents to two or more points along the polymerbackbone or side chains or polymer termini.

[0069] In alternative embodiments, the control agents of this inventionhave a ring structure, which upon ring opening may form amulti-functional control agent. Thus, in some embodiments, formulas (I)and (II) above are arranged so that D is sulfur, R³ is deleted, and thenitrogen atom from which R³ was deleted forms a ring with R¹ providinggeneral formulas:

[0070] wherein the above variables have the same definitions, with theexception that R¹ is a biflnctional moiety within the definitions givenabove. In a particularly preferred embodiment, R¹ comprises—CH(R⁵)—C(O)— such that formulas (XI) and (XII) can be redrawn as:

[0071] wherein R², R⁴, Q, Q′ and n are as defined above. R⁵ is selectedfrom the group consisting of hydrogen, hydrocarbyl, substitutedhydrocarbyl, heteroatom-containing hydrocarbyl, and substitutedheteroatom-containing hydrocarbyl, and combinations thereof. Inparticular, R⁵ is selected from the group consisting of hydrogen,optionally substituted alkyl, optionally substituted aryl, optionallysubstituted alkenyl, optionally substituted acyl, optionallysubstituted, aroyl, and optionally substituted alkoxy. Preferred R⁵groups include hydrogen, methyl, ethyl, propyl, butyl, methoxy, ethoxy,propoxy, phenoxy and phenyl. As above, R⁴ and R² can combine to form aring structure having from 4 to 50 non-hydrogen atoms.

[0072] In some embodiments within formulas (XIII) and (XIV), R² may beindependently selected from —Q(═Q′)_(n)(R^(4′)—Q′)_(m)(R⁴)_(p). In theseembodiments, Q, Q′, R⁴, R^(4′), n, m and p have the above stateddefinitions.

[0073] In other alternative embodiments, the multi-functional controlagents of this invention can be characterized by any of the followingformulas (which may fall within the general formulas given above):

[0074] wherein R¹, R², R³ and R⁴ are as defined above. In formula (XVI),the moiety

[0075] refers to a ring structure having between 3 and 20 non-hydrogenatoms in the ring, including single ring or multiple rings that arefused together, linked covalently, or linked to a common group such as amethylene or ethylene moiety. R⁶ is a substituent on any member of thering other than the two shown nitrogen atoms. There may be as many R⁶substituents as ring members in addition to the two nitrogen atoms. R⁶substituents may be selected from the group consisting of hydrocarbyl,substituted hydrocarbyl, heteroatom-containing hydrocarbyl, andsubstituted heteroatom-containing hydrocarbyl, and combinations thereof.In particular, R⁶ is selected from the group consisting of optionallysubstituted alkyl, optionally substituted aryl, optionally substitutedalkenyl, optionally substituted acyl, optionally substituted, aroyl, andoptionally substituted alkoxy.

[0076] Specific cyclic/multi-functional control agents include:

[0077] Cyclic

[0078] Multi-Functional

[0079] The control agents of this invention are synthesized, generally,by methods known to those of skill in the art. The general syntheticapproach comprises the nitrogen nucleophilic addition to carbondisulfide and alkylation of the resulted dithiocarbazate withalkylhalides in a one-pot methodology, as shown in the following scheme2:

[0080] This method is similar to those published in scientific journals,e.g., Castro et al., J. Org. Chem., 1984, 49, 863, which is incorporatedherein by reference.

[0081] The synthesis conditions optimized for these particularnucleophiles—hydrazines and their derivatives include: temperature inthe range of 0° C. to ambient; solvents—alcohols, acetone, acetonitrile,dioxane, DMF, DMSO; base—sodium hydroxide, potassium hydroxide, andsodium hydride. The preferred conditions include using sodium hydroxideas the base in DMSO at ambient temperature.

[0082] The general procedure comprises starting with the hydrazine orits derivative dissolved in DMSO in approximately a 0.5-1.0 Mconcentration at ambient temperature. The solution is then treated withapproximately 1 equivalent of NaOH and followed by addition ofapproximately 1 equivalent of carbon disulfide. The resulting solutionis then stirred (for example, for approximately 1 hour at ambienttemperature) before addition of approximately 1 equivalent of analkylation agent. Work-up may comprise addition of water, extractionwith organic solvent, and drying. The desired control agent may bepurified by chromatography and/or recrystallization and may becharacterized by ¹H NMR, ¹³C NMR, and GC/MS.

[0083] Most of hydrazines and their derivatives are availablecommercially from known chemical sources. However, to increasing thediversity of the control agents, several transformations may be applied,including:

[0084] 1. hydrazone formation as shown in scheme 3:

[0085] 2. hydrazide formation as shown in scheme 4:

[0086] 3. sulfonylhydrazine formation as shown in scheme 5:

[0087] 4. phosphoryl hydrazine formation as shown in scheme 6:

[0088] 5. Urea and urethane derivatives formation as shown in scheme 7:

[0089]  In scheme 7, Z is used to denote the variables shown in formula(II), above.

[0090] 6. Cyclic hydrazine derivatives formation as shown in scheme 8:

[0091]  In scheme 8, R′ is used to represent the various R groupsdiscussed herein (e.g., R², R³ and/or R⁴).

[0092] The cyclic control agents for example as shown below may beprepared from an appropriate alkylation agent which can subsequentlyreact with another nitrogen of the hydrazine, as shown below in scheme9:

[0093] Those of skill in the -art will appreciate that scheme 9 can bemodified to obtain desired substituents, as shown in generally informulas (XIII) and (XIV), above.

[0094] Polymerization Processes

[0095] The polymerization conditions that may be used includetemperatures for polymerization typically in the range of from about 20°C. to about 110° C., more preferably in the range of from about 50° C.to about 90° C. and even more preferably in the range of from about 60°C. to about 80° C. The atmosphere may be controlled, with an inertatmosphere being preferred, such as nitrogen or argon. The molecularweight of the polymer is controlled via adjusting the ratio of monomerto control agent. Generally, the molar ratio of monomer to control agentis in the range of from about 5 to about 5000, more preferably in therange of from about 10 to about 2000, and most preferably from 10 toabout 1500.

[0096] A free radical source is provided in the polymerization mixture,which can stem from spontaneous free radical generation upon heating orpreferably from a free radical initiator. In the latter case theinitiator is added to the polymerization mixture at a concentration highenough to for an acceptable polymerization rate (e.g., commerciallysignificant conversion in a certain period of time, such as listedbelow). Conversely, a too high free radical initiator to control agentratio will favor unwanted dead polymer formation through radical-radicalcoupling reaction leading to polymer materials with uncontrolledcharacteristics. The molar ratio of free radical initiator to controlagent for polymerization are typically in the range of from about 2:1 toabout 0.02:1.

[0097] Polymerization conditions also include the time for reaction,which may be from about 0.5 hours to about 72 hours, preferably in therange of from about 1 hour to about 24 hours, more preferably in therange of from about 2 hours to about 12 hours. Conversion of monomer topolymer is preferably at least about 50%, more preferably at least about75% and most preferable at least about 85%.

[0098] The polymerization process generally proceeds in a “living” typemanner. Thus, generally an approximately linear relationship betweenconversion and number average molecular weight can be observed, althoughthis is not a pre-requisite. The living character manifests itself bythe ability to prepare block copolymers: hence, a polymer chain is firstgrown with monomer A, and then, when monomer A is depleted, monomer B isadded to extend the first block of polymer A with a second block ofpolymer B. Thus, in some instances, particularly when the chain transferconstant of the control agent, Ct, is low (Ct being defined as the ratioof the transfer rate coefficient to the propagation rate constant),e.g., Ct less than 2, the molecular weight to conversion plot might notexhibit a linear trend: this does not preclude however that blockcopolymer formation did not occur. Block copolymer formation through aliving process can be demonstrated using analytical techniques such aspolymer fractionation with selective solvent (of polymer A, polymer B,respectively), gradient elution chromatography and/or 2-dimensionalchromatography. Block copolymers tend to microphase-separate andorganize in a variety of morphologies that can be probed by physicaltechniques such as X-ray diffraction, dynamic mechanical testing, andthe like.

[0099] Initiators, as discussed above, may be optional. When present,initiators useful in the polymerization mixture and the inventiveprocess are known in the art, and may be selected from the groupconsisting of alkyl peroxides, substituted alkyl peroxides, arylperoxides, substituted aryl peroxides, acyl peroxides, alkylhydroperoxides, substituted alkyl hydroperoxides, aryl hydroperoxides,substituted aryl hydroperoxides, heteroalkyl peroxides, substitutedheteroalkyl peroxides, heteroalkyl hydroperoxides, substitutedheteroalkyl hydroperoxides, heteroaryl peroxides, substituted heteroarylperoxides, heteroaryl hydroperoxides, substituted heteroarylhydroperoxides, alkyl peresters, substituted alkyl peresters, arylperesters, substituted aryl peresters, and azo compounds. Specificinitiators include benzoylperoxide (BPO) and AIBN. The polymerizationmixture may use a reaction media is typically either an organic solventor bulk monomer or neat. Optionally, after the polymerization is over(e.g., completed or terminated) the thio-moiety (e.g., a dithio-moiety)of the control agent can be cleaved by chemical or thermal ways, if onewants to reduce the sulfur content of the polymer and prevent anyproblems associated with presence of the control agents chain ends, suchas odor or discoloration. Typical chemical treatment includes thecatalytic or stoichiometric addition of base such as a primary amine,acid or anhydride, or oxidizing agents such as hypochlorite salts.

[0100] Generally, monomers that may be polymerized using the methods ofthis invention (and from which M, below, may be derived) include atleast one monomer is selected from the group consisting of styrene,substituted styrene, alkyl acrylate, substituted alkyl acrylate, alkylmethacrylate, substituted alkyl methacrylate, acrylonitrile,methacrylonitrile, acrylamide, methacrylamide, N-alkylacrylamide,N-alkylmethacrylamide, N,N-dialkylacrylamide, N,N-dialkylmethacrylamide,isoprene, butadiene, ethylene, vinyl acetate and combinations thereofFunctionalized versions of these monomers may also be used. Specificmonomers or comonomers that may be used in this invention include methylmethacrylate, ethyl methacrylate, propyl methacrylate (all isomers),butyl methacrylate (all isomers), 2-ethylhexyl methacrylate, isobornylmethacrylate, methacrylic acid, benzyl methacrylate, phenylmethacrylate, methacrylonitrile, α-methylstyrene, methyl acrylate, ethylacrylate, propyl acrylate (all isomers), butyl acrylate (all isomers),2-ethylhexyl acrylate, isobomyl acrylate, acrylic acid, benzyl acrylate,phenyl acrylate, acrylonitrile, styrene, glycidyl methacrylate,2-hydroxyethyl methacrylate, hydroxypropyl methacrylate (all isomers),hydroxybutyl methacrylate (all isomers), N,N-dimethylaminoethylmethacrylate, N,N-diethylaminoethyl methacrylate, triethyleneglycolmethacrylate, itaconic anhydride, itaconic acid, glycidyl acrylate,2-hydroxyethyl acrylate, hydroxypropyl acrylate (all isomers),hydroxybutyl acrylate (all isomers), N,N-dimethylaminoethyl acrylate,N,N-diethylaminoethyl acrylate, triethyleneglycol acrylate,methacrylamide, N-methylacrylamide, N,N-dimethylacrylamide,N-tert-butylmethacrylamide, N-n-butylmethacrylamide,N-methylolmethacrylamide, N-ethylolmethacrylamide,N-tert-butylacrylamide, N-n-butylacrylamide, N-methylolacrylamide,N-ethylolacrylamide, 4-acryloylmorpholine, vinyl benzoic acid (allisomers), diethylaminostyrene (all isomers), α-methylvinyl benzoic acid(all isomers), diethylamino α-methylstyrene (all isomers),p-vinylbenzene sulfonic acid, p-vinylbenzene sulfonic sodium salt,trimethoxysilylpropyl methacrylate, triethoxysilylpropyl methacrylate,tributoxysilylpropyl methacrylate, dimethoxymethylsilylpropylmethacrylate, diethoxymethylsilylpropyl methacrylate,dibutoxymethylsilylpropyl methacrylate, diisopropoxymethylsilylpropylmethacrylate, dimethoxysilylpropyl methacrylate, diethoxysilylpropylmethacrylate, dibutoxysilylpropyl methacrylate, diisopropoxysilylpropylmethacrylate, trimethoxysilylpropyl acrylate, triethoxysilylpropylacrylate, tributoxysilylpropyl acrylate, dimethoxymethylsilylpropylacrylate, diethoxymethylsilylpropyl acrylate, dibutoxymethylsilylpropylacrylate, diisopropoxymethylsilylpropyl acrylate, dimethoxysilylpropylacrylate, diethoxysilylpropyl acrylate, dibutoxysilylpropyl acrylate,diisopropoxysilylpropyl acrylate, maleic anhydride, N-phenylmaleimide,N-butylmaleimide, butadiene, isoprene, chloroprene, ethylene, vinylacetate and combinations thereof.

[0101] In some embodiments of the polymers of this invention, acombination of hydrophobic and hydrophilic monomers may be used, eitherrandomly or in separate blocks of a copolymer (e.g., thermoplasticelastomers, grafts, etc). The hydrophobic/hydrophilic nature of monomersmay be determined according to the log P of the particular monomers,which is sometimes referred to as the octanol-water partitioncoefficient. Log P values are well known and are determined according toa standard test that determines the concentration of monomer in awater/1-octanol separated mixture. In particular, computer programs arecommercially available as well as on the internet that will estimate thelog P values for particular monomers. Some of the log P values in thisapplication were estimated from the web sitehttp://esc.syrres.com/interkow/kowdemo.htm, which provides an estimatedlog P value for molecules by simply inserting the CAS registry number ora chemical notation. Log P values listed herein were obtained fromeither the web site listed above or from Hansch et al. Exploring QSAR:Hydrophobic, Electronic, and Steric Constants (ACS ProfessionalReference Book, 1995), which is incorporated herein by reference.

[0102] Suitable hydrophilic monomers (with approximate log P valueslisted in parentheses) may be listed above and include, but are notlimited to, acrylic acid (0.35), methacrylic acid (0.93),N,N-dimethylacrylamide (−0.13), dimethyl aminoethyl methacrylate (0.97),quaternized dimethylaminoethyl methacrylate, methacrylamide (−0.26),N-t-butyl acrylamide (1.02), maleic acid (−0.48), maleic anhydride andits half esters, crotonic acid (0.72), itaconic acid (−0.34), acrylamide(−0.67), acrylate alcohols, hydroxyethyl methacrylate, diallyldimethylammonium chloride, vinyl ethers (such as methyl vinyl ether),maleimides, vinyl pyridine, vinyl imidazole (0.96), other polar vinylheterocyclics, styrene sulfonate, allyl alcohol (0.17), vinyl alcohol(such as that produced by the hydrolysis of vinyl acetate afterpolymerization), salts of any acids and amines listed above, andmixtures thereof. Preferred hydrophilic monomers include acrylic acid,N,N-dimethyl acrylamide (−0.13), dimethylaminoethyl methacrylate (0.97),quatemized dimethyl aminoethyl methacrylate, vinyl pyrrolidone, salts ofacids and amines listed above, and combinations thereof.

[0103] Suitable hydrophobic monomers may be listed above and include,but are not limited to, acrylic or methacrylic acid esters of C₁-C₁₈alcohols, such as methanol, ethanol, methoxy ethanol, 1-propanol,2-propanol, 1-butanol, 2-methyl-1-propanol, 1-pentanol, 2-pentanol,3-pentanol, 2-methyl-1-butanol, 1-methyl-1-butanol, 3-methyl-1-butanol,1-methyl-1-pentanol, 2-methyl-1-pentanol, 3-methyl-1-pentanol, t-butanol(2-methyl-2-propanol), cyclohexanol, neodecanol, 2-ethyl-1-butanol,3-heptanol, benzyl alcohol, 2-octanol, 6-methyl-1-heptanol,2-ethyl-1-hexanol, 3,5-dimethyl-1-hexanol, 3,5,5-tri methyl-1-hexanol,1-decanol, 1-dodecanol, 1-hexadecanol, 1-octa decanol, and the like, thealcohols having from about 1 to about 18 carbon atoms, preferably fromabout 1 to about 12 carbon atoms; styrene; polystyrene macromer, vinylacetate; vinyl chloride; vinylidene chloride; vinyl propionate;alpha-methylstyrene; t-butylstyrene; butadiene; cyclohexadiene;ethylene; propylene; vinyl toluene; and mixtures thereof. Preferredhydrophobic monomers (with approximate log P values listed inparentheses) include n-butyl methacrylate (2.36), isobutyl methacrylate(2.66), t-butyl acrylate (2.09), t-butyl methacrylate (2.54),2-ethylhexyl methacrylate (4.09), methyl methacrylate (1.38), vinylacetate (0.73), vinyl acetamide, vinyl formamide, and mixtures thereof,more preferably t-butyl acrylate, t-butyl methacrylate, or combinationsthereof.

[0104] In addition, monomers that polymerize in a ring closing methodmay also be used in this invention, including monomers that are of theformula: CH₂═CH—X′—CH═CH₂ where X′ comprises from 1 to 20 non-hydrogenatoms. Such monomers are well known in the art. A specific example is{CH₂═CH—N(CH₃)₂—CH═CH₂}⁺{Cl}⁻.

[0105] Polymers

[0106] The polymers formed with the chain transfer agents of thisinvention are believed to be grown via a degenerative transfermechanism. Thus, upon analysis of the obtained polymers, monomers mightappear between the R¹—S bond, and any of the above formulas can berewritten in a polymeric form. For example, the polymers of thisinvention may be characterized by the general formula:

[0107] wherein M is a monomer or mixture of monomers or at least 2blocks of different monomer (any from the above lists) and f is thedegree of polymerization, and D, R¹, R², R³ and R⁴ are as defined above.

[0108] For the more specific embodiment, the polymer of this invention,the polymers may be characterized by the general formula:

[0109] wherein M is a monomer or mixture of monomers or at least 2blocks of different monomer (any from the above lists) and f is thedegree of polymerization, and Q, Q′, n, D, R¹, R², R³ and R⁴ are asdefined above.

[0110] Free radical polymerization of cyclic monomers by ring openingmechanism is known (see, e.g., The Chemistry Of Free RadicalPolymerization, G. Moad, D. H. Solomon, Eds. (Pergamon Pub., 1995), p176-183). However no commercially viable process has been developed sofar. This is due at least in part to the poor reactivity of thesemonomer compounds (e.g., Ketene acetals) as well as their relativeinstability to water traces. Moreover, known polymerization mechanismsfor ring opening polymerization systems are not know for theirliving-type kinetics.

[0111] Surprisingly it has been found that the cyclized forms of themulti-functional control agents (such as those described by formulas(XIII) and (XIV)) lead to ring opening reaction under polymerizationconditions. The polymer thus formed may be characterized by the generalformula:

[0112] where R², R⁴ and R⁵ have the same definitions given above and Arepresents a repeat unit of block of monomer A (with n″ being the degreeof polymerization of the block; m″ being the number of repeat units ofthe block with the attached control agent; and * representing the endsof the polymer). The molecular weight of the polymer formed from monomerA is generally controlled by controlling the monomer to control agentratio in the polymerization mixture, as discussed above.

[0113] As formula (XXI) shown, the multi-functional control agents ofthis invention also provide, in some embodiments, for a dithiocarbazatecompound (i.e., N—NC(═S)S) in the backbone of a carbon-carbon polymerchain, such as usually obtained by free radical polymerization ofethylenic monomers. This is desirable for several applications: forinstance, such polymers can be reduced to low molecular weight materialby applying external stimuli such as UV, light, heat, biochemical orchemical treatment, which are known to cleave thiocarbonylthio linkage.Such polymers could be used as thermoplastics susceptible to degradationby exposure to sunlight, or by enzymatic digestion since it is knownthat short polymers chains are readily biodegradable.

[0114] Moreover, multiblock copolymers (ABx)_(y) can be obtained in atwo-step process, by first preparing a first multiblock homopolymer,denoted (Ax)_(y), where x represents the dithiocarbazate N—NC(═S)Smoiety and y represents the number of A or AB blocks and y is 2 or more,and then adding monomer B , in order to get (ABx)_(y), which may becharacterized by the general formula:

[0115] where R², R⁴ and R⁵ and n″ and m″ have the same definitions givenabove, A represents a repeat unit of block of monomer A and B representsa repeat unit of block of monomer B and o″ is the degree ofpolymerization of monomer B. Monomers A and B can be selected from anyof the above lists. Copolymers having a similar structure as (AB)_(y)copolymers are usually prepared by multiple sequential addition ofdifferent monomers with the usual pitfalls such as loss of control aslong as the number of block increase or contamination of block A with Bmonomers. This new process alleviates these difficulties.

[0116] The formulas for multifunctional control agents can also bewritten in polymer form, as follows:

[0117] wherein each of the variable in formulas (XXIII) to (XXXI) havethe above stated meanings.

[0118] In some embodiments of this invention, it is desirable to make ablock copolymer, such as for example with both hydrophobic andhydrophilic monomers, with these monomers being selected from the abovelists. In this case, the monomers M in the above formulas will be A andB or more blocks.

[0119] As used herein, “block copolymer” refers to a polymer comprisingat least two segments of differing composition; having any one of anumber of different architectures, where the monomers are notincorporated into the polymer architecture in a solely statistical oruncontrolled manner. Although there may be three, four or more monomersin a single block-type polymer architecture, it will still be referredto herein as a block copolymer. In some embodiments, the block copolymerwill have an A-B architecture (with “A” and “B” representing themonomers). Other architectures included within the definition of blockcopolymer include A-B-A, A-B-A-B, A-B-C, A-B-C-A, A-B-C-A-B, A-B-C-B,A-B-A-C (with “C” representing a third monomer), and other combinationsthat will be obvious to those of skill in the art. Block copolymers canbe prepared a number of ways, including sequential addition of monomersor using multi-functional control agents described above. Of course withmulti-functional control agents, the control agent may form a linkinggroup between one or more blocks of the copolymers.

[0120] In another embodiment, the block copolymers of this inventioninclude one or more blocks of random copolymer together with one or moreblocks of single monomers. Thus, a polymer architecture of A-R, A-R-B,A-B-R, A-R-B-R-C, etc. is included herein, where R is a random block ofmonomers A and B or of monomers B and C. Moreover, the random block canvary in composition or size with respect to the overall block copolymer.In some embodiments, for example, the random block R will account forbetween 5 and 80% by weight of the mass of the block copolymer. In otherembodiments, the random block R will account for more or less of themass of the block copolymer, depending on the application. Furthermore,the random block may have a compositional gradient of one monomer to theother (e.g., A:B) that varies across the random block in an algorithmicfashion, with such algorithm being either linear having a desired slope,exponential having a desired exponent (such as a number from 0.1-5) orlogarithmic. The random block may be subject to the same kineticeffects, such as composition drift, that would be present in any otherradical copolymerization and its composition, and size may be affectedby such kinetics, such as Markov kinetics. Any of the monomers listedelsewhere in this specification may be used in the block copolymers ofthis invention.

[0121] A “block” within the scope of the block copolymers of thisinvention typically comprises about 10 or more monomers of a single type(with the random blocks being defined by composition and/or weightpercent, as described above). In preferred embodiments, the number ofmonomers within a single block is about 15 or more, about 20 or more orabout 50 or more. However, in an alternative embodiment, the blockcopolymers of this invention include blocks where a block is defined astwo or more monomers that are not represented elsewhere in thecopolymer. This definition is intended to encompass adding small amountsof a second monomer at one or both ends of a substantially homopolymericpolymer. In this alternative embodiment, the same copolymerarchitectures discussed above apply. This definition is thereforeintended to include telechelic polymers, which include one or morefunctional end groups capable of reacting with other molecules. Thus,generally, a telechelic polymer is a block copolymer with in thedefinitions of this invention. The functional groups present at one orboth ends of a telechelic polymer may be those known to those of skillin the art, including, for example, hydroxide, aldehyde, carboxylic acidor carboxylate, halogen, amine and the like, which have the ability toassociate or form bonds with another molecule. Likewise, the blockcopolymers of the invention are intended to encompass telechelicpolymers containing bifunctional groups, such as allyl-terminated orvinyl-terminated telechelics, sometimes referred to as macromonomers ormacromers because of their ability to participate in polymerizationreactions through the terminal functional group.

[0122] Combining the above embodiments provides a particularly powerfulmethod of designing block copolymers. For example, a block copolymer mayhave the architecture F-A-B-F, where F represents functional groups thatmay be the same or different within a single F-A-B-F structure (which,therefore, may encompass F-A-B-F′). Other block copolymer architectureswithin the scope of this invention include A-R-B-F and F-A-R-B-F. Otherarchitectures will be apparent to those of skill in the art upon reviewof this specification—indeed, without wishing to be bound by anyparticular theory—it is the living nature of the emulsions of thisinvention that provide the ability to even make these novel blockcopolymers.

[0123] In one embodiment, block copolymers are assembled by thesequential addition of different monomers or monomer mixtures to livingpolymerization reactions. In another embodiment, the addition of apre-assembled functionalized block (such as a telechelic oligomer orpolymer) to a living free radical polymerization mixture yields a blockcopolymer. Ideally, the growth of each block occurs to high conversion.Conversions are determined by size exclusion chromatography (SEC) viaintegration of polymer to monomer peak. For UV detection, the polymerresponse factor must be determined for each polymer/monomerpolymerization mixture. Typical conversions can be 50% to 100% for eachblock. Intermediate conversion can lead to block copolymers with arandom copolymer block separating the two or more homopolymer blocks,depending on the relative rates of polymerization and monomer addition.At high conversion, the size of this random block is sufficiently smallsuch that it is less to affect polymer properties such as phaseseparation, thermal behavior and mechanical modulus. This fact can beintentionally exploited to improve polymerization times for manyapplications without measurably affecting the performancecharacteristics of the resulting polymer. This is achieved byintentionally “killing” or terminating the living nature of thepolymerization when a desired level of conversion (e.g., >80%) isreached by neutralizing the control agent, for example by introducingacids, bases, oxidizing agents, reducing agents, radical sources,scavengers, etc. In the absence of control agent, the polymerizationcontinues uncontrolled (typically at much higher reaction rates) untilthe remaining monomer is consumed. Block copolymer can also be createdby grafting monomers, monomer mixtures, oligomers or polymers onlypolymers having multiple available functional groups.

[0124] In other embodiments, block copolymers can be prepared bygrafting processes, preparation of telechelic polymers, preparation ofmacromonomers, etc. In these embodiments, at least one polymer segmentis derived from a living or controlled process of the invention, whileother segments can be derived from any polymerization process,including, for example, controlled or uncontrolled radicalpolymerization, condensation polymerization, Ziegler-Natta and relatedprocesses, Ring-Opening Metathesis Polymerization, ionic polymerization,surface modification or grafting, or other addition or step-growthprocesses.

[0125] Block copolymers allow the combination of potentially diversepolymer properties (such as hard/soft and/or hydrophilic/hydrophobic(amphiphilic) blocks) into a single polymer chain. Hard/soft blockcopolymers combine segments with significantly different glasstransition temperatures T_(g). A typical hard/soft copolymer pairs arelatively “hard” block (e.g., styrene) with a relatively “soft” block(e.g., butyl acrylate). The resulting materials can possess performanceattributes not found in any of the constituent segments. The presence ofmicrophase separation and various phase morphologies in block copolymersis associated with unique performance attributes of many blockcopolymers. For example, by combining the stiffness or rigiditycharacteristic of hard materials with the compliance of soft materials,block copolymers may exhibit advantageous properties, such asprocessability under melt conditions, elasticity, resistance to abrasionand cracking and desired creep characteristics (corresponding to thematerial's ability to hold its shape under external stresses) dependingon morphology, making them appropriate for use as extrudable bulkmaterials, coatings and separation media. The exact properties of ahard/soft copolymer depend significantly on the difference between theglass transition temperatures of the constituent blocks; accordingly,selection of monomers having glass transition temperatures a particulardistance apart can lead to hard/soft block copolymers having particulardesired characteristics. Thus, while for one application it may beappropriate to combine blocks having glass transition temperatures thatdiffer by, for example, 20° C., the choice of T_(g) (and therefore ofmaterials) depends on the application.

[0126] Likewise, the amphiphilic block copolymers produced according tothe invention display combinations of hydrophobic and hydrophilicproperties that make such materials appropriate for use as surfactantsor dispersants, scavengers, surface treatments and the like. Differentblock sizes over all ratios of monomers and molecular weights lead tofamilies of novel compounds, for example thermoplastics, elastomers,adhesives, and polymeric micelles.

[0127] Multi-arm or star polymers can be generated using initiatorscapable of initiating multiple free radical polymerizations under thecontrolled conditions of the invention. Such initiators include, forexample polyfunctional chain transfer agents, discussed above. Followinginitiation, the growth of each arm is controlled by the same livingkinetics described for linear polymers, making it possible to assemblestar polymers whose arms include individual homopolymers as well as di,tri or higher order block copolymers. Alternatively, multi-arm polymersare formed by growing end-functionalized oligomers or polymers followedby the addition of a cross-linking monomer such as ethylene glycoldiacrylate, divinyl benzene, methylene bisacrylamide, trimetylol propanetriacrylate, etc. The small hydrodynamic volume of star polymersproduced according to these methods provides properties such as lowviscosity, high M_(w), and high functionality useful in applicationssuch as rheology control, thermosets, and separation media. Similarly,the inclusion of branched or multiple ethylenically unsaturated monomersenables the preparation of graft polymers, again exhibiting the livingkinetics characteristic of this invention. The existence of a blockcopolymer according to this invention is determined by methods known tothose of skill in the art, including nuclear magnetic resonance (NMR),measured increase of molecular weight upon addition of a second monomerto chain-extend a living polymerization of a first monomer, microphaseseparation (e.g., long range order, microscopy and/or birefringencemeasurements), mechanical property measurements, (e.g., elasticity ofhard/soft block copolymers), thermal analysis and chromatography (e.g.,absence of homopolymer).

EXAMPLES

[0128] General: Syntheses of control agents were carried out under anitrogen or argon atmosphere. Other chemicals were purchased fromcommercial sources and used as received, except for monomers, which werefiltered through a short column of basic aluminum oxide to remove anyinhibitor and degassed by applying vacuum. All polymerization mixtureswere prepared in a glove box under a nitrogen or argon atmosphere andsealed, and polymerization was conducted at 60° C. or 70° C. SizeExclusion Chromatography was performed using an automated rapid GPCsystem for the primary screening (see WO 99/51980, incorporated hereinby reference) and using automated conventional GPC system for secondaryscreening. In the current setup N,N-dimethylformamide containing 0.1% oftrifluoroacetic acid was used as an eluent for the rapid GPC systemwhereas THF for the conventional system and polystyrene-based columns.All of the molecular weight results obtained are relative to linearpolystyrene standards. NMR was carried out using a Bruker spectrometer(300 MHz) with CDCl₃ (chloroform-d) as solvent.

Example 1

[0129]

[0130] A 50 mL round-bottomed flask equipped with a magnetic stir barand maintained under a nitrogen atmosphere was charged with hydrazineA′-1 (4.0 g, 20 mmol), sodium hydroxide (0.8 g, 20 mmol), and ethanol(20 mL). The reaction mixture was kept cold in an ice/water bath. To theresulting solution, carbon disulfide (1.21 mL, 20 mmol) was addeddropwise. The mixture was stirred for an additional one hour after theaddition was finished. Ethyl 2-bromopropionate (2.6 mL, 20 mmol) wasthen added to the reaction mixture at 0° C. After the reaction wascompleted, as monitored by thin layer chromatography (TLC), the reactionmixture was poured into 80 mL of water and followed by extraction withethyl acetate (2×80 mL). The organic layer was further washed with water(2×80 mL) and dried over MgSO₄. The solvent was removed under reducedpressure and the product was further purified by flash chromatograph.The desired control agent A-1 was obtained in 72% yield (5.4 g).

Example 2

[0131]

[0132] A 50 mL round-bottomed flask equipped with a magnetic stir barand maintained under a nitrogen atmosphere was charged with hydrazineB′-1 (1.6 g, 10 mmol), sodium hydroxide (0.4 g, 10 mmol), and DMSO (20mL). The reaction mixture was kept cold in an ice/water bath. To theresulting solution, carbon disulfide (0.6 mL, 10 mmol) was addeddropwise. The mixture was stirred for an additional one hour after theaddition was finished. Ethyl 2-bromopropionate (1.81 g, 1.3 mL) was thenadded to the reaction mixture at 0° C. After the reaction was completed,as monitored by TLC, the reaction mixture was poured into 80 mL of waterand followed by extraction with ethyl ether (2×80 mL). The organic layerwas further washed with water (2×80 mL) and dried over MgSO₄. Thesolvent was removed under reduced pressure and the product was furtherpurified by flash chromatograph. The desired control agent B-1 wasobtained in 67% yield (1.6 g).

Example 3

[0133]

[0134] A 100 mL round-bottomed flask was charged with hydrazine C″-1 (3mL, 30 mmol), and acetone (20 mL) at ambient temperature. The excess ofacetone was removed under reduced pressure to give a quantitative yieldof hydrazone C′-1. The flask then equipped with a magnetic stir bar andmaintained under a nitrogen atmosphere was charged with sodium hydroxide(1.2 g, 30 mmol), and dimethylsulfoxide (DMSO) (60 mL) at ambienttemperature. The reaction mixture was kept in a water bath. To theresulting solution, carbon disulfide (1.8 mL, 30 mmol) was addeddropwise. The mixture was stirred for an additional one hour after theaddition was finished. Ethyl 2-bromopropionate (3.9 mL, 30 mmol) wasthen added to the reaction mixture dropwise. After the reaction wascompleted, as monitored by TLC, the reaction mixture was poured into 120mL of water and followed by extraction with ethyl acetate (2×80 mL). Theorganic layer was further washed with water (2×80 mL) and dried overMgSO₄. The solvent was removed under reduced pressure and the productwas further purified by flash chromatograph. The desired control agentC-1 was obtained in 65% yield (6.3 g).

Example 4

[0135]

[0136] A 100 mL round-bottomed flask equipped with a magnetic stir barand maintained under a nitrogen atmosphere was charged with pyrazoleD′-1 (1.36 g, 20 mmol), sodium hydroxide (0.8 g, 20 mmol), and DMSO (40mL). The reaction mixture was kept in an ice/water bath. To theresulting solution, carbon disulfide (1.2 mL, 20 mmol) was addeddropwise. The mixture was stirred for an additional one hour after theaddition was finished. Ethyl 2-bromopropionate (2.6 mL, 20 mmol) wasthen added to the reaction mixture dropwise. After the reaction wascompleted, as monitored by TLC, the reaction mixture was poured into 80mL of water and followed by extraction with ethyl acetate (2×80 mL). Theorganic layer was further washed with water (2×80 mL) and dried overMgSO₄. The solvent was removed under reduced pressure and the productwas further purified by flash chromatograph. The desired control agentD-1 was obtained in 85% yield (4.15 g).

Example 5

[0137]

[0138] A 100 mL round-bottomed flask equipped with a magnetic stir barand maintained under a nitrogen atmosphere was charged with pyrazoleE′-1 (1.36 g, 20 mmol), sodium hydroxide (0.8 g, 20 mmol), and DMSO (40mL). The reaction mixture was kept in an ice/water bath. To theresulting solution, carbon disulfide (1.2 mL, 20 mmol) was addeddropwise. The mixture was stirred for an additional one hour after theaddition was finished. Benzyl bromide (2.38 mL, 20 mmol) was then addedto the reaction mixture dropwise. After the reaction was completed,monitored by TLC, the reaction mixture was poured into 80 mL of waterand followed by extraction with ethyl acetate (2×80 mL). The organiclayer was further washed with water (2×80 mL) and dried over MgSO₄. Thesolvent was removed under reduced pressure and the product was furtherpurified by flash chromatograph. The desired control agent E-1 wasobtained in 91% yield (4.3 g).

Example 6

[0139]

[0140] A 100 mL round-bottomed flask equipped with a magnetic stir barand maintained under a nitrogen atmosphere was charged with hydrazineF′-1 (6 mL, 30 mmol), sodium hydroxide (1.2 g, 30 mmol), and DMSO (60mL). The reaction mixture was kept in an ice/water bath. To theresulting solution, carbon disulfide (1.8 mL, 30 mmol) was addeddropwise. The mixture was stirred for an additional one hour after theaddition was finished. Ethyl 2-bromopropionate (3.9 mL, 30 mmol) wasthen added to the reaction mixture dropwise. After the reaction wascompleted, as monitored by TLC, the reaction mixture was poured into 120mL of water and followed by extraction with ethyl acetate (2×80 mL). Theorganic layer was further washed with water (2×80 mL) and dried overMgSO₄. The solvent was removed under reduced pressure. The crudematerial was purified by silica gel column chromatography. The desiredcontrol agent F-1 was obtained in 55% yield (3.93 g).

Examples 7-15

[0141] These examples demonstrate polymerization of various monomersusing control agents of this invention, specifically control agents A-1,B-1, C-2 and F-1, whose synthesis is described above. Each of thepolymerizations was carried out in the same general way, which is that a0.6M stock solution of each control agent in THF was first prepared. Foreach polymerization a single monomer was used in the amount of 3 mmol.2,2′-azobis(2-methylpropionitrile) (AIBN) was the initiator used in eachpolymerization in a quantity of 10 mole % relative to the control agent.The control agent in each polymerization was 0.5 mole % relative to theamount of monomer. The polymerization mixture of each reaction wascreated by automated dispensing of reaction components at roomtemperature into a glass vial, which was then sealed. Eachpolymerization reaction was carried out at 60° C. for a time of 1 hour,4 hours, 12 hours and 16 hours; thus, for each example, thepolymerization was carried out four times, once for each time period.The monomers used were styrene (Sty), vinyl acetate (VA), and methylacrylate (MA), each of which was used in neat form and prepared asdiscussed at the beginning of the example section. The results of thesepolymerizations are reported in Table 1, below.

[0142] A series of control experiments was also carried put, where thesame polymerization mixtures were created, but no control agent wasadded. The results of those control experiments are not reported indetail because gels or very high molecular weight polymers wereobtained. TABLE 1 Control Reaction Example Agent Monomer Time (hrs)M_(n) M_(w)/M_(n) 7 A-1 Sty 1 38900 1.57 4 35700 1.54 12 36600 1.57 1633700 1.61 8 A-1 VA 1 N/A N/A 4 9500 1.14 12 9300 1.14 16 10200 1.14 9A-1 MA 1 65000 1.37 4 71300 1.32 12 73000 1.32 16 64700 1.37 10 B-1 Sty1 N/A N/A 4 5300 1.09 12 5600 1.09 16 6500 1.12 11 B-1 MA 1 N/A N/A 4N/A N/A 12 8300 1.16 16 12000 1.17 12 C-1 Sty 1 97300 1.12 4 55600 1.4712 58300 1.5 16 51500 1.58 13 C-1 MA 1 39800 1.31 4 47700 1.32 12 399001.36 16 44400 1.34 14 F-1 Sty 1 N/A N/A 4 68500 1.35 12 70700 1.38 1654600 1.51 15 F-1 MA 1 273800 1.26 4 N/A N/A 12 263400 1.45 16 2181001.44

Example 16

[0143] This example shows butyl acrylate homopolymerization in thepresence of the control agent B-1 (which was prepared as above) and inthe absence of control agent.

[0144] Freshly prepared n-butyl acrylate (5727 uL) and CTA-3 (68 mg) inthree reaction vessels were added with 50 uL, 150 uL, and 300 uL of AIBNstock solution (32.8 mg/mL in toluene), respectively. In addition, ablank reaction with no control agent was prepared with 50 uL of AIBNstock solution. The polymerizations were carried out at 60° C. for 15hours in glass vessels that were sealed.

[0145] The results are reported in Table 2 and conventional GPC wasperformed on the samples: TABLE 2 AIBN Entry (mole % to B-1) Mn Mw/MnConv. (%) 1 10 2500 1.60 24 2 30 9400 1.53 50 3 60 14200 1.51 72 4 0.05mole % of Crosslinked material monomer

Example 17

[0146] Butyl acrylate and Styrene homopolymerization in the presence ofthe control agent E-1, as shown above.

[0147] A stock solution mixture of freshly prepared n-butyl acrylate(5727 uL), control agent E-1 (46.8 mg), and AIBN solution in aconcentration of 32.8 mg/mL in toluene (50 uL) was split into 5 glass 4mL reaction vessels. Another stock solution mixture of freshly preparedStyrene (4577 uL), control agent E-1 (46.8 mg), and AIBN solution in aconcentration of 32.8 mg/mL in toluene (50 uL) was also split into 5glass 4 mL reaction vessels. The polymerizations were carried out at 60°C. and 70° C. for 1 to 22 hours.

[0148] The results are reported in Table 3 and conventional GPC wasperformed on the samples: TABLE 3 Temp. Time Entry Monomer (° C.) (h) MnMw/Mn Conv. (%) 1 n-butyl acrylate 60 2 15700 1.12 70 2 n-butyl acrylate60 4 18000 1.12 86 3 n-butyl acrylate 60 15 19600 1.14 94 4 n-butylacrylate 70 1 17400 1.16 85 5 n-butyl acrylate 70 15 20600 1.19 97 6Styrene 60 4 2900 1.47 11 7 Styrene 60 15 5000 1.37 32 8 Styrene 60 226900 1.24 47 9 Styrene 70 4 4300 1.40 19 10 Styrene 70 22 6700 1.28 41

[0149] It is to be understood that the above description is intended tobe illustrative and not restrictive. Many embodiments will be apparentto those of skill in the art upon reading the above description. Thescope of the invention should, therefore, be determined not withreference to the above description, but should instead be determinedwith reference to the appended claims, along with the full scope ofequivalents to which such claims are entitled. The disclosures of allarticles and references, including patent applications and publications,are incorporated herein by reference for all purposes.

What is claimed is:
 1. A method of free radical polymerizationcomprising (1) forming a mixture of one or more monomers, at least onefree radical source and a control agent and (2) subjecting said mixtureto polymerization conditions, wherein said control agent contains atleast one N—N bond covalently bonded to a thiocarbonyl group.
 2. Themethod of claim 1, wherein said control agent is characterized by thegeneral formula:

wherein R¹ is any group that group that can be expelled as its freeradical form in an addition-fragmentation reaction; R² and R³ are eachindependently selected from the group consisting of hydrogen,hydrocarbyl, substituted hydrocarbyl, heteroatom-containing hydrocarbyl,and substituted heteroatom-containing hydrocarbyl, and combinationsthereof, and optionally R² and R³ together to form a double bondoptionally substituted alkenyl moiety; R⁴ is selected from the groupconsisting of hydrogen, hydrocarbyl, substituted hydrocarbyl,heteroatom-containing hydrocarbyl, and substituted heteroatom-containinghydrocarbyl, and combinations thereof; and optionally, R⁴ combines withR² and/or R³ to form a ring structure, with said ring having from 3 to50 non-hydrogen atoms; and D is either sulfur, selenium or tellurium. 3.The method of claim 2 wherein said control agent is characterized by thegeneral formula:

wherein Q is selected from the group consisting of carbon, sulfur andphosphorus; Q′ is selected from the group consisting of oxygen andsulfur; R^(4′) is selected from the same group as R⁴; and each of n, mand p is 0, 1 or 2 to satisfy the valency of Q.
 4. The method of eitherof claims 1, 2 or 3, wherein an initiator is the source of freeradicals.
 5. The method of claim 3 wherein D is sulfur, Q is carbon, Q′is oxygen and n is
 1. 6. The method of claim 4, wherein R⁴ is selectedfrom the group consisting of optionally substituted alkyl and optionallysubstituted aryl.
 7. The method of either of claims 2 or 3, wherein R¹is selected from the group consisting of optionally substituted alkyl,optionally substituted aryl, optionally substituted alkenyl, optionallysubstituted alkoxy, optionally substituted heterocyclyl, optionallysubstituted alkylthio, optionally substituted amino and optionallysubstituted polymer chains.
 8. The method of either of claims 2 or 3,wherein R¹ is selected from the group consisting of —CH₂Ph,—CH(CH₃)CO₂CH₂CH₃, —CH(CO₂CH₂CH₃)₂, —C(CH₃)₂CN, —CH(Ph)CN and—C(CH₃)₂Ph.
 9. The method of either of claims 2 or 3, wherein R² and R³are each independently selected from the group consisting of hydrogen,optionally substituted alkyl, optionally substituted aryl, optionallysubstituted alkenyl, optionally substituted acyl, optionallysubstituted, aroyl, optionally substituted alkoxy, optionallysubstituted heteroaryl, optionally substituted heterocyclyl, optionallysubstituted alkylsulfonyl, optionally substituted alkylsulfinyl,optionally substituted alkylphosphonyl, optionally substitutedarylsulfinyl, and optionally substituted arylphosphonyl.
 10. The methodof either of claims 2 or 3, wherein R⁴ is selected from the groupconsisting of hydrogen, optionally substituted alkyl, optionallysubstituted aryl, amino, thio, optionally substituted aryloxy andoptionally substituted alkoxy.
 11. The method of either of claims 1, 2or 3, wherein said polymerization conditions comprise a temperature inthe range of from about 20° C. to about 110° C.
 12. The method of eitherof claims 1, 2 or 3, wherein two or more monomers are added to saidpolymerization mixture and said two or more monomers are addedsequentially or simultaneously.
 13. The method of either of claims 1, 2or 3, wherein said polymerization conditions comprise living kinetics.14. A polymer formed by the method of any of claims 1, 2 or
 3. 15. Thepolymer of claim 14, wherein said copolymer is a block copolymer.
 16. Amethod of method of free radical polymerization comprising (1) forming amixture of one or more monomers, at least one free radical source and amulti-functional control agent and (2) subjecting said mixture topolymerization conditions, wherein said control agent contains at leastone N—N bond covalently bonded to a thiocarbonyl moiety.
 17. The methodof claim 16, wherein said multi-functional control agent is selectedfrom any of the following formulas:

wherein R¹ is any group that group that can be expelled as its freeradical form in an addition-fragmentation reaction; R² and R³ are eachindependently selected from the group consisting of hydrogen,hydrocarbyl, substituted hydrocarbyl, heteroatom-containing hydrocarbyl,and substituted heteroatom-containing hydrocarbyl, and combinationsthereof; and optionally R² and R³ together to form a double bondoptionally substituted alkenyl moiety; R⁴ and R⁴ are each independentlyselected from the group consisting of hydrogen, hydrocarbyl, substitutedhydrocarbyl, heteroatom-containing hydrocarbyl, and substitutedheteroatom-containing hydrocarbyl, and combinations thereof; andoptionally, R⁴ combines with R² and/or R³ to form a ring structure, withsaid ring having from 3 to 50 non-hydrogen atoms; D is either sulfur,selenium or tellurium; Q is selected from the group consisting ofcarbon, sulfur and phosphorus; Q′ is selected from the group consistingof oxygen and sulfur; and each of n, m and p is 0, 1 or 2 to satisfy thevalency of Q; Core is a core molecule, and c is 1 or more and d is 2 ormore; R⁵ is selected from the group consisting of hydrogen, hydrocarbyl,substituted hydrocarbyl, heteroatom-containing hydrocarbyl, andsubstituted heteroatom-containing hydrocarbyl, and combinations thereof;

 R refers to a ring structure having between 3 and 20 non-hydrogen atomsin the ring, including single ring or multiple rings that are fusedtogether, linked covalently, or linked to a common group; and R⁶ is asubstituent on any member of the ring other than the two shown nitrogenatoms.
 18. The method of either of claims 16 or 17, wherein an initiatoris the source of free radicals.
 19. The method of claim 17, wherein R¹is selected from the group consisting of optionally substituted alkyl,optionally substituted aryl, optionally substituted alkenyl, optionallysubstituted alkoxy, optionally substituted heterocyclyl, optionallysubstituted alkylthio, optionally substituted amino and optionallysubstituted polymer chains.
 20. The method of claim 17, wherein R¹ isselected from the group consisting of —CH₂Ph, —CH(CH₃)CO₂CH₂CH₃,—CH(CO₂CH₂CH₃)₂, —C(CH₃)₂CN, —CH(Ph)CN and —C(CH₃)₂Ph.
 21. The method ofclaim 17, wherein R² and R³ are each independently selected from thegroup consisting of hydrogen, optionally substituted alkyl, optionallysubstituted aryl, optionally substituted alkenyl, optionally substitutedacyl, optionally substituted, aroyl, optionally substituted alkoxy,optionally substituted heteroaryl, optionally substituted heterocyclyl,optionally substituted alkylsulfonyl, optionally substitutedalkylsulfinyl, optionally substituted alkylphosphonyl, optionallysubstituted arylsulfinyl, and optionally substituted arylphosphonyl. 22.The method claim 17, wherein R⁴ is selected from the group consisting ofhydrogen, optionally substituted alkyl, optionally substituted aryl,amino, thio, optionally substituted aryloxy and optionally substitutedalkoxy.
 23. The method of either of claims 16 or 17, wherein saidpolymerization conditions comprise a temperature in the range of fromabout 20° C. to about 110° C.
 24. The method of either of claims 16 or17, wherein two or more monomers are added to said polymerizationmixture and said two or more monomers are added sequentially orsimultaneously.
 25. The method of either of claims 16 or 17, whereinsaid polymerization conditions comprise living kinetics.
 26. A polymerformed by the method of any of claims 16 or
 17. 27. The polymer of claim26, wherein said copolymer is a block copolymer.
 28. The polymer ofclaim 26, wherein said polymer is a star or hyperbranched polymer.
 29. Acompound characterized by the formula:

wherein R¹ is selected from the group consisting of hydrocarbyl,substituted hydrocarbyl, heteroatom-containing hydrocarbyl, andsubstituted heteroatom-containing hydrocarbyl, and combinations thereof,with the proviso that R¹ is not methyl; R² and R³ are each independentlyselected from the group consisting of hydrogen, hydrocarbyl, substitutedhydrocarbyl, heteroatom-containing hydrocarbyl, and substitutedheteroatom-containing hydrocarbyl, and combinations thereof, and R⁴ isselected from the group consisting of hydrogen, hydrocarbyl, substitutedhydrocarbyl, heteroatom-containing hydrocarbyl, and substitutedheteroatom-containing hydrocarbyl, and combinations thereof; andoptionally, R⁴ combines with R² and/or R³ to form a ring structure, withsaid ring having from 3 to 50 non-hydrogen atoms.
 30. The compound ofclaim 29, wherein R¹ is selected from the group consisting of optionallysubstituted alkyl, optionally substituted aryl, optionally substitutedalkenyl, optionally substituted alkoxy, optionally substitutedheterocyclyl, optionally substituted alkylthio, optionally substitutedamino and optionally substituted polymer chains.
 31. The compound ofclaim 30, wherein R¹ is selected from the group consisting of —CH₂Ph,—CH(CH₃)CO₂CH₂CH₃, —CH(CO₂CH₂CH₃)₂, —C(CH₃)₂CN and —C(CH₃)₂Ph.
 32. Thecompound of claim 29, wherein R² and R³ are each independently selectedfrom the group consisting of hydrogen, optionally substituted alkyl,optionally substituted aryl, optionally substituted alkenyl, optionallysubstituted acyl, optionally substituted, aroyl, optionally substitutedalkoxy, optionally substituted heteroaryl, optionally substitutedheterocyclyl, optionally substituted alkylsulfonyl, optionallysubstituted alkylsulfinyl, optionally substituted alkylphosphonyl,optionally substituted arylsulfinyl, and optionally substitutedarylphosphonyl.
 33. A compound characterized by the formula:

wherein R¹ is selected from the group consisting of hydrocarbyl,substituted hydrocarbyl, heteroatom-containing hydrocarbyl, andsubstituted heteroatom-containing hydrocarbyl, and combinations thereof;R² and R³ are each independently selected from the group consisting ofhydrogen, hydrocarbyl, substituted hydrocarbyl, heteroatom-containinghydrocarbyl, and substituted heteroatom-containing hydrocarbyl, andcombinations thereof, and R⁴ is selected from the group consisting ofhydrogen, hydrocarbyl, substituted hydrocarbyl, heteroatom-containinghydrocarbyl, and substituted heteroatom-containing hydrocarbyl, andcombinations thereof; and optionally, R⁴ combines with R² and/or R³ toform a ring structure, with said ring having from 3 to 50 non-hydrogenatoms.
 34. The compound of claim 33, wherein R¹ is selected from thegroup consisting of optionally substituted alkyl, optionally substitutedaryl, optionally substituted alkenyl, optionally substituted alkoxy,optionally substituted heterocyclyl, optionally substituted alkylthio,optionally substituted amino and optionally substituted polymer chains.35. The compound of claim 34, wherein R¹ is selected from the groupconsisting of 13 CH₂Ph, —CH(CH₃)CO₂CH₂CH₃, —CH(CO₂CH₂CH₃)₂, —C(CH₃)₂CNand —C(CH₃)₂Ph.
 36. The compound of claim 33, wherein R² and R³ are eachindependently selected from the group consisting of hydrogen, optionallysubstituted alkyl, optionally substituted aryl, optionally substitutedalkenyl, optionally substituted acyl, optionally substituted, aroyl,optionally substituted alkoxy, optionally substituted heteroaryl,optionally substituted heteroeyclyl, optionally substitutedalkylsulfonyl, optionally substituted alkylsulfinyl, optionallysubstituted alkylphosphonyl, optionally substituted arylsulfinyl, andoptionally substituted arylphosphonyl.